A wireless local area network (abbreviated as WLAN) system operates at an unlicensed spectrum, and the unlicensed spectrum belong to public spectrums. Thus, a transmitting station needs to compete for a channel before sending data.
In conventional technology, the transmitting station needs to detect a busy/free state of the channel during competing for the channel. After waiting until the channel is free for a period of time, the transmitting station may reserve the channel and send data through the reserved channel, or directly send the data without reserving the channel. In conventional technology, a maximum duration of occupancy of the channel is a fixed value no matter whether the channel is busy or not. The duration that the transmitting station reserves the channel each time can not exceed the maximum duration. In a case that the channel is free, if the transmitting station needs to send too many data, the transmitting station can not send all the data through the channel reserved this time even though the duration of reservation of the channel is equal to the maximum duration. Thus, the transmitting station needs to compete for the channel more than once, which increases the complexity for sending data by the transmitting station. While, in a case that the channel is busy, if the transmitting station only needs to send a few data and still reserves the channel for the maximum duration, reserved channel resources will be wasted, thus the utilization of channel resources is not high.